Why is defining intelligence so controversial?
- Ethnicity, race & culture, Socioeconomic Background, Individual differences, and Multiple domains of knowledge
- Standardized test scores have been found to correlate with SES and ethnic minority status and favor
rich kids from majority ethnic backgrounds
- Ironically they were developed to eliminate subjectivity from the testing process
- Standford-Binet is among the best tests in providing appropriate cautions for test users
Three research traditions used to study human intelligence
- Psychometric
- Information-processing
- Cognitive
Examines properties of test by evaluating what other variables it correlates to or existing underlying dimensions
Examines the processes that underlie how we learn and solve problems
Examines how humans adapt to the demands of their environments
Applications of Intelligence Testing (1-3)
1. Evaluating brain damage, high/low mental ability (assignment of mentally challenged/ gifted children to special classes) 2. Screening, placement, and classification of: -----students in higher education institutions -----employees in business/ industry -----military/ gov. personnel 3. Vocational (occupational) and educational counseling and rehab
Applications of intelligence testing (4-6)
4. Psycho-diagnosis of children & adults in clinical or psychiatric context 5. Evaluating effectiveness of psychological treatments and environmental interventions 6. Research on cognitive abilities and personality
Type of Intelligence Tests
1. Individual intelligence tests 2. Group intelligence tests
Individual intelligence tests
Administered to understand individual's cognitive strengths and weaknesses, used to make decisions about the individual
- Used for screening purposes to predict academic and occupational performance
- more economical
- sometimes have higher validity
- 1905 Binet-Simon scale in France – Standardization samples, individualized test
- Revised for use in the United States by L. Terman of Stanford University – Stanford-Binet Intelligence Scale
Binet Definition of Intelligence
1) Is the capacity to find and maintain definite direction or purpose 2) Is the capacity to make necessary adaptations or adjust strategies to achieve that purpose 3) Is the capacity to engage in self-criticism so that the adjustment in strategy can be made
- Operationalized through tasks related to judgmental, attentional, and
reasoning facilities
Binet's methods used to create tasks
- Trial-and-error
- Experimentation
- Hypothesis-Testing
Binet's two major concepts
- Age differentiation
- General mental ability
Binet Achieving Age Differentiation
Find or create tasks that:
- 67%-75% of children of a specific age can complete task
- A larger portion of older children could complete task
- A smaller portion of younger children could complete task
Completing a particular age differentiation task --> Estimate of mental ability independent of chronological age EX: a 4-year-old completes a task designed for the average 6-year-old --> The 4-year-old has a mental ability of a 6-year-old --> this child's MENTAL AGE would be 6
Binet General Mental Ability
Binet considered the different tasks measured a general mental ability as opposed to different elements of ability
Spearman's Model of Mental Ability
- General Mental Intelligence (g), "g factor"---responsible for overall performance on a mental ability test
- Based on a well documented phenomenon that if you give a large sample of people an array of diverse ability tests, their scores on each test are positively correlated with one another (positive manifold), basically a correlation between tests for each individual subject
----- Used to reduce a set of scores or variables to a smaller # of hypothetical variables
----- Can be used to determine how much common variance there is between a set of scores or variables
----- This common
variance represents the g factor
----- Approximately half the variance in a set of diverse mental-ability tests is represented in the g factor
-----Developed by Spearman
Two basis forms of intelligence
- Fluid intelligence (gf)
- Crystallized intelligence (gc)
(GF) Abilities that allow us to reason, think and acquire new knowledge
Crystallized intelligence
(GC) Represents the knowledge and understanding that has already been acquired
- 30 items with increasing level of difficulty
- Problem: only measured reading, language, and verbal skills
- Used outdated terms like ‘idiot’, ‘imbecile’, ‘moron’ to categorize adults
- Problems: No measuring unit, No adequate normative data, No validity evidence
- 1908 version grouped items by age level (age scale) and not by difficulty level
- Mental age concept introduced
1916 Stanford-Binet Intelligence Scale (revised by Lewis Terman)
Retained:
-----Principle of age differentiation
-----Principle of general mental intelligence
-----Principle of age scales
-----Mental age concept
Revised:
-----Increased standardization sample
-----Age range increased (3-14)
-----Added new items
-----Introduced the IQ concept
1916 version introduced the IQ (intelligence quotient) Step 1: find subjects Chronological Age (CA) (birthday) Step 2: Find subject's mental age (MA) (test score) Step 3: IQ=(MA/CA)*100 EXAMPLE: Subject 1: CA=10, MA=10, 10/10=1*100=100: Average Subject 2: CA=10, MA=13, 13/10=1.3*100=130: Faster-than-average mental development Subject 3: CA=10, MA=7, 7/10=.7*100=70: slower-than-average mental development
1937 Binet Scale Improvements
- General improvements:
Extended age range (2 yr olds), increased mental age (22 yrs , 10 months), Scoring standards improved to standardize administration and increase interscorer reliability, added performance items that decreased scale's emphasis on verbal skills
- Increased standardization sample to about 3100 (only whites)
- Added an equivalent form (L and M)
-----added in 1937 -----designed to be equivalent forms in terms of both difficulty and content -----psychometric properties of the scale could now be examined -----combined in 1960 revision
1937 Binet Scale Psychometric Properties
- reliability: generally excellent but varies as function of age and IQ, less reliable at younger age ranges and higher IQ levels
- differential variability in IQ as a function of age exists
- validity: generally supported by correlational studies, and factor analytic studies
1937 Binet Scale Problems
- Less reliable at younger ages and higher IQ levels
- Different age groups had different variability in IQ scores -> IQs at one age level were not equivalent to IQs at a different age level
- Resolved the problem of differential variation in IQ scores by creating new IQ tables that corrected for variations at different age levels
- Rejected the IQ concept and introduced the deviation IQ (mean = 100, SD = 16)
- Combined forms L and M
- 1972 a new standardization sample what included ethnic/racial minorities
Modern Binet Scale: 1986 and 2003 Scales
- Incorporated gf-gc theory of intelligence
- 1986 revisions included items of the same content that were placed together into one of 15 different tests
- g--- 1. GC crystallized abilities (verbal reasoning, nonverbal reasoning), 2. GF fluid-analytic abilities, and 3. short-term memory
-----Uses both point scales and age
scales with both verbal and non verbal subtests weighted equally
-----Uses adaptive testing through a routing test (one verbal one nonverbal) that were on a point scale, used to estimate level of ability (starting point)–skip easy items
-----Remaining 8 subtests were on an age-scale (diff content grouped together and ordered in increasing difficulty)
-----Basal & ceiling
- level at which the minimum criterion number
of correct responses is obtained
- the age level reached when the examinee has answered all questions correctly
- Keep going from basal level until they reach ceiling---when a certain number of incorrect responses is given
2003 Binet Scale Psychometric properties
- Spans 2 to 85+ years of age
- Standardization sample of 4,800 stratified by gender, ethnicity, region and educational level (3,000 additional special population samples)
- Reliability around .97
- The validity of measuring 5 factors has been recently challenged
Cut-off boundaries for the full scale scores
145-160: very gifted 130-144: gifted 120-129: superior 110-119: high average 90-109: average 80-89: low average 70-79: borderline impaired/ delayed 55-69: mildly impaired/ delayed 40-54: moderately impaired/ delayed
discrimination based on the fact that older children have greater capabilities than do younger children
A test in which items are grouped according to age level (The Binet scale, for example, grouped into one age level items that 2/3 to 3/4 of a representative group of children at a specific age could successfully pass
On the Wechsler tests, a standard score with a mean of 10 and SD of 3
A test that consists of tasks that require a subject to do something rather than to answer questions
Alfred Binet on Intelligence
Judgement, otherwise called "good sense," "practical sense," "initiative," the faculty of adapting oneself to circumstances... auto-critique
David Wechsler on Intelligence
The aggregate or global capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment
Lloyd Humphreys on Intelligence
"...the resultant of the process of acquiring, storing in memory, retrieving, combining, comparing, and using in new contexts information and conceptual skills"
Cyril Burt on Intelligence
Innate general cognitive ability
Howard Gardner on Intelligence
To my mind, a human intellectual competence must entail a set of skills of problem solving---enabling the individual to resolve problem or difficulties that he or she encounters and, when appropriate, to create an effective product---an dust all entail the potential for finding or creating problems---and thereby laying the groundwork for the acquisition of new knowledge
Linda Gottfredson on Intelligence
The ability to deal with cognitive complexity
Goal-directed adaptive behavior
The theory of Structural Cognitive Modifiability describes intelligence as "the unique propensity of human beings to change or modify the structure of their cognitive functioning to adapt to the changing demands of a life situation